Sore Shoulder

The deltoid muscle is the large rounded muscle that lies over the top of the shoulder joint. It's main job is to move the arm outwards and upwards away from the body - although the many different directions that it's fibre strands take has led modern anatomists to suspect that it actually does much more than the old textbooks would have us believe.

Deltoid muscle pain is common - or, it's true to say that pain in the region of the deltoid muscle is common ... but actual injury to that muscle is rare. The structure of the muscle means that it's not likely to be injured by lifting or by a fall. The other smaller rotator cuff muscles that lie beneath it are much more vulnerable to injury. If these smaller muscles are damaged or become inflamed then the mechanism called referred pain often leads the brain to think that it's deltoid that's at fault.